Aggregate dryer



AGGREGATE DRYER W. M. MADSEN Filed Feb. 23, 1954 rlllll Dec. 10, 1957 Mkm INVENTORQ Waller Madsen Unite St AGGREGATE DRYER Walter M. Madsen,Arcadia, Calif.

Application February 23, 1954, Serial No. 411,706

12 Claims. (Cl. 259-3) This invention relates generally to dryingequipment and relates more particularly to apparatus for drying varioustypes of aggregates used in the paving industry and the like.

While the present apparatus has particular utility in the heating anddrying of aggregates, such as rock, sand, etc. used in the asphaltpaving industry and is shown and described in connection with drum typedryers used in said industry, it is to be understood that its utility isnot confined thereto.

In the asphalt paving industry, it is necessary to dry as well as heatthe rocks and sand aggregates. These aggregates are fed or delivered tothe dryer from a suitable source such as a feed bunker or tunnel byvarious means such as, for example, a conveyor belt or elevator.

Various problems are encountered in drum type dryers used for dryingvarious aggregates and it is an object of the present invention toprovide a dryer that is highly efficient and effective.

Another object of the invention is to provide a dryer of this characterhaving a maximum opening within the shell so as to provide maximumproductive capacity.

Still another object of the invention is to provide apparatus of thischaracter adapted to effectively handle a greater amount of materialthan heretofore.

A further object of the invention is to provide apparatus of thischaracter wherein the material is carried further up and over as thedryer shell is rotated.

A further object of the invention is to provide apparatus of thischaracter wherein there is a delay in dropping of the material withinthe dryer shell.

A still further object of the invention is to reduce the number ofchannel lifters required.

Another object of the invention is to provide apparatus of thischaracter which will more uniformly create aggregate curtain wallsthroughout the entire dryer int'erior.

Still another object of the invention is to provide apparatus of thischaracter that is relatively simple in construction.

A further object of the invention is to provide apparatus of thischaracter that is relatively inexpensive to manufacture.

Other objects and advantages of the invention will appear from thefollowing part of the specification.

Referring more particularly to the drawings, which are for illustrativepurposes only,

Fig. 1 is a side elevation of apparatus embodying the present invention,there being portions broken away showing certain interior structuralfeatures;

Fig. 2 is a sectional view taken on line 2--2 of Fig. l; and

Fig. 3 is a sectional view taken on line 33 of Fig. 1.

Referring more particularly to the drawings, there is shown acylindrical shell 16 arranged substantially horiz-ontally, the inlet end11 being higher than the outlet end 12. The shell is provided with aplurality of longitudinally spaced rows of annularly spaced elongated2,815,940 Patented Dec. 10, 1951 openings which are substantiallyparallel to the axis of the shell and the openings of the rows arestaggered with respect to the openings of adjacent rows. The openings 14may be of any suitable shape but are disclosed herein as being generallyrectangular with the length of said openings extending longitudinallywith respect to the length of the shell.

Within the shell is provided material lifting means shown herein ascomprising a plurality of longitudinally spaced rows of annularly spacedchannel members or lifters, indicated generally at 15. The lifters 15are channel-shaped or U-shaped in cross-section and have arms 16 securedto the interior wall of the shell. The opposite arms 17 extend in thedirection of rotation of the device, which direction of rotation isindicated by the arrows 19. The lifters are secured to the shell bymeans of welding or other suitable means and at the back thereof areangle irons or members 20 which are secured to the shell and to therespective lifters by suitable means such as welding or the like. Themembers 20 are at the backs of the lifters 15 and 'serve to strengthensame.

The lifters 15 are adjacent to the leading edges 31 of the openings 14and are arranged in generally parallel relationship therewith.

On the exterior of the shell 10, there are a plurality of longitudinallyspaced rows of annularly spaced pockets 25, each of which is defined bya casing, indicated generally at 26 and comprising arcuately shapedwalls 27 and end walls 28. There is a pocket for each opening 14 andsaid pockets are arranged generally parallel to the axis of the shell.Each casing 26 is substantially wider at its open end than the width ofthe respective opening 14 and said casing is secured to the exterior ofthe shell by means of welding or the like. It is to be noted that theleading edge 30 of each casing is located adjacent the leading edge 31of the respective opening 14 and the trailing edge or side 32 of thecasing is spaced rearwardly of the trailing edge 22 of said opening sothat there is a portion 35 of the shell wall which serves to partiallydefine the respective pocket.

Means for rotatably supporting the above described mechanism comprises aplurality of annular rings 37 which encircle the shell and pockets, saidrings being spaced apart longitudinally with respect to the shell. Therings 37 are shown as being secured to the outer portions of the walls27 of the casings 26 but it is to be understood that said rings may beotherwise mounted. The rings rest on rollers 38 carried by shafts 39which are mounted in bearings 40 carried by a frame, indicated generallyat 42. The frame includes longitudinally extending beams 43.

Between the rings 37 is a gear ring suitably secured to the casings 26,said ring being connected by a chain 46 to a sprocket 47 mounted on ashaft 48 having bearings 49 carried by transverse beams 50 secured tothelongitudinal beams 43; The shaft 48 extends longitudinally of theapparatus to the forward end thereof and is provided with additionalbearings 52. Means for driving the shaft comprises an electric motor 53which is connected to a gear reduction mechanism 54 having a sprocket 55connected to a sprocket 56 on the shaft 48 by means of a chain 57.

Material to be heated and dried by the apparatus is delivered to theinlet end 11 by any suitable means shown as comprising a chute 61) whichprojects into the shell through an inlet opening 61 of smaller diameterthan the diameter of the shell. provided with a plurality of spiralflanges or vanes 63 which provide means for feeding aggregate materialquickly into the dryer and away from the inlet end so as to preventcongestions which might otherwise develop.

In operation, as the shell is rotated, the. material is de- The inletend portion 62 is.

livered to the inlet and is moved further into the shell by the flangesor vanes 63. This material enters the lowermost pockets 25 by passingthrough the respective openings 14- and this pocket of material, as wellas material picked up by the lifters 15, will be carried upwardly. Asthe material is thus carried up, a point is reached whereat saidmaterial begins to fall from the lifters and some of the pocketedmaterial will begin to fall. The

falling material forms curt ins with the sh ll so that the heated airmovin throu h the shell w ll quickly dr and heat the m terial. It is tobe noted that the pocketed material will be carried further up and overduring the rotati n of the drver shell than occurs wi h the materialpicked no by the lifters. With the combination of pockets and lifters.there are curtain walls over substantially the entire interior of theshell.

As additional material enters the shell and is moved inwardly by thevanes or flan es 63. the body f material moves toward the outlet andthere is handled successively by the rows B. C. D and E of the a aratusfrom which it will pass outwardly and be discharged from the outlet end.

I claim:

1. Apparatus for drying various a regates used in the paving industryand the like, comprising: a cylindrical shell having an inlet at one endand an outlet at the other end. said shell having a plurality oflongitudinally spaced rows of annularlv spaced enerally rectangularopenings therein substantially parallel to the axis of said shell. theopenings of the rows being sta ered with respect to the openin s ofadiacent rows; a plurality of spiral flan es at the inlet end forfeeding material into the drver; a plurality of longitudinally s acedrows of annularly spaced channel lifters, there being a lifter securedto the shell interior adiacent each opening at the leading side thereof.the lifters of each row being parallel to each other and extendingparallel to the axis of the shell, the lifters of the rows beingstaggered with respect to the lifters of adjacent rows; a plurality oflongitudinally spaced rows of annularly spaced casing members, therebeing a casing member for each opening in the shell secured to theexterior thereof to provide staggered rows of annularly spaced pocketsparallel to the axis of the shell, each casing member comprising anarcuate wall and end walls. the casing member being open at its widestside, the leading side of each casing member being generally alignedwith the leading edge of its respective shell opening, the width of saidcasing members being substantially greater than the width of theopenings so that the portions of the shell covered by the casing membersat the trailing sides of the openings partially define said pockets andprovide walls adapted to carry material upwardly at the upwardly'movingside of the shell as said shell rotates and from which curtains ofmaterial gradually drop with further rotation of said shell; means forrotatably mounting said shell with the inlet end higher than thheuoutletend; and means for effecting rotation of said s e 2. In apparatus fordrying various aggregates used in the paving industry and the like: acylindrical shell hav- 1ng an inlet at one end and an outlet at theother end, said shell having a plurality of longitudinally spaced rowsof annularly spaced generally rectangular openings therein substantiallyparallel to the axis of said shell, the openngs of the rows beingstaggered with respect to the openrngs of adjacent rows; a plurality ofspiral flanges at the inlet end for feeding material into the dryer; aplurality of longitudinally spaced rows of annularly spaced channellifters, there being a lifter secured to the shell interior adjacenteach opening at the leading side thereof, the lifters of each row beingparallel to each other and extending parallel to the axis of the shell,the lifters of the rows being staggered with respect to the lifters ofadjacent rows; a plurality of longitudinally spaced rows of annularlyspaced casing members, there being a casing member for each opening inthe shell secured to the exterior thereof to provide staggered rows ofannularly' spaced pockets parallel to the axis of the shell, each casingmember comprising an arcuate wall and end walls, the casing member beingopen at its widest side, the leading side of each casing member beinggenerall aligned with the leading edge of its respective shell opening,the width of said casing members being substantially greater than thewidth of the openings so that the portions of the shell covered by thecasing members at the trailing sides of the openings partially definesaid pockets and provide walls adapted to carry material upwardly at theupwardly moving side of the shell as said shell rotates and from whichcurtains of material gradually drop with further rotation of said shell;and means for rotatably mounting said shell with the inlet end higherthan the outlet end.

3. In apparatus for drying various aggregates used in the pavingindustry and the like: a cylindrical shell having an inlet at one endand an outlet at the other end, said shell having a plurality oflongitudinally spaced rows of annularly spaced elongated openingstherein substantially parallel to the axis of said shell, the openingsof the rows being staggered with respect to the openings of adjacentrows; a plurality of spiral flanges at the inlet end for feedingmaterial into the dryer; a channel lifter secured to the shell interioradjacent each opening at the leading side thereof; a casing member foreach opening in the shell secured to the exterior thereof to provideexternal pockets, each casing member being generally semi-circular incross section and being open at its widest side, the leading side ofeach casing member being generally aligned with the leading edge of itsrespective shell opening, the width of said casing members beingsubstantially greater than the width of the openings so that theportions of the shell covered by the casing members at the trailingsides of the openings partially define said pockets and provide wallsadapted to carry material upwardly at the upwardly moving side of theshell as said shell rotates and from which curtains of materialgradually drop with further rotation of said shell; and means forrotatably mounting said shell with the inlet end higher than the outletend.

4. In apparatus for drying various aggregates used in the pavingindustry and the like: a cylindrical shell having an inlet at one endand an outlet at the other end, said shell having a plurality oflongitudinally spaced rows of annularly spaced elongated openingstherein substantially parallel to the axis of said shell, the openingsof the rows being staggered with respect to the openings of adjacentrows; a plurality of spiral flanges at the inlet end for feedingmaterial into the dryer; a channel lifter secured to the shell interioradjacent each opening at the leading side thereof; a casing member foreach opening in the shell secured to the exterior thereof to provideexternal pockets, each casing member being generally semi-circular incross section and being open at its widest side, the leading side ofeach casing member being generally aligned with the leading edge of itsrespective shell opening, the width of said casing members beingsubstantially greater than the width of the openings so that theportions of the shell covered by the casing members at the trailingsides of the openings partially define said pockets and provide wallsadapted to carry material upwardly at the upwardly moving side of theshell as said shell rotates and from which curtains of materialgradually drop with further rotation of said shell; and means forrotatably mounting said shell.

5. In apparatus for drying various aggregates used in the pavingindustry and the like: a tubular shell having an inlet at one end and anoutlet at the other end, said shell having a plurality of longitudinallyspaced rows of annularly spaced generally rectangular openings thereinsubstantially parallel to the axis of said shell; a channel liftersecured to the shell interior adjacent each opening at the leading sidethereof to gradually drop material, from the upwardly moving side of theshell as it rotates to a point approximately at the uppermost rotationpoint for said shell; a casing member over each opening in the shellsecured to the exterior thereof to provide external pockets, the widthof said casing members being substantially greater than the width of theopenings with portions of the shell at the trailing sides of theopenings covered by the casing members to provide walls adapted to carrymaterial upwardly at the upwardly moving side of the shell as said shellrotates and from which curtains of material gradually drop with furtherrotation of said shell beyond the uppermost rotation point for saidshell; and means for rotatably mounting said shell.

6. In apparatus for drying various aggregates used in the pavingindustry and the like: a tubular shell having an inlet at one end and anoutlet at the other end, said shell having a plurality of longitudinallyspaced rows of annularly spaced generally rectangular openings thereinsubstantially parallel to the axis of said shell, the openings of therows being staggered with respect to the openings of adjacent rows;material lifters secured to the shell interior adjacent respectiveopenings at the leading sides thereof; a casing over each opening in theshell secured to the exterior thereof to provide external pockets, thewidth of said casings being substantially greater than the width of theopenings and said casings covering portions of the shell at the trailingsides of the openings; and means for rotatably mounting said shell.

7. In apparatus for drying various aggregates used in the pavingindustry and the like: a rotatably mounted tubular shell having an inletat one end and an outlet at the other end, said shell having a pluralityof longitudinally spaced rows of annularly spaced generally rectangularopenings therein substantially parallel to the axis of said shell;material lifters secured to the shell interior adjacent respectiveopenings at the leading sides thereof, the lifters being parallel toeach other and extending parallel to the axis of the shell; and meansdefining pockets externally of the shell, there being a pocket for eachopening, said openings communicating with respective pockets, eachpocket having a material retaining portion disposed on the trailing sideof the opening with which it communicates.

8. In apparatus of the class described: a rotatably mounted shell havingan inlet at one end and an outlet at the other end; means defining aplurality of annularly spaced pockets on the exterior of the shell andparallel to the axis of said shell, said shell having openings thereinproviding communication between the interior of said shell and saidpockets with the pockets having material retaining portions disposed onthe trailing side of the openings in rotation of said shell; andmaterial lifting means operably associated with said openings interiorlyof said shell.

9. In apparatus for drying various aggregates used in the pavingindustry and the like: a rotatably mounted tubular shell; means defininga plurality of annularly spaced elongated pockets on the exterior ofsaid shell, said shell having an elongated opening therein for eachpocket, said openings being narrower than said pockets with asubstantial portion of each pocket being disposed on the trailing sideof the opening with which it communicates; and material lifting means onthe interior of said shell operably associated with said openings.

10. In apparatus of the class described: a tubular shell having aplurality of openings therein; and a casing member over each opening inthe shell secured to the exterior thereof to provide exterior pockets,the width of said casing members being substantially greater than thewidth of the openings with a portion of the shell at the trailing sideof each of the openings covered by the casing members to provide wallsadapted to carry material upwardly at the upwardly moving side of theshell as said shell rotates and from which curtains of materialgradually drop as said shell rotates.

11. In apparatus for drying various aggregates used in the pavingindustry and the like, a rotatable tubular shell through which the hotdrying gases pass in drying the particulate aggregate material, saidshell being mounted for rotation about its longitudinal axis and havingan inlet for aggregate material at one end and an outlet at the otherend, a first series of material lifting means carried by andperipherally spaced around the wall of said shell with each liftingmeans in said series including a wall member extending inwardly of thewall of said shell and disposed to carry material upwardly and graduallydrop such material to the point at which the wall member reachesapproximately the uppermost point in the rotary movement of said shell,a second series of material lifting means carried by and peripherallyspaced around the wall of said shell with each lifting means of saidsecond series including a pocket carried by said shell having a materialretaining portion and a mouth opening into the shell interior, thematerial retaining portion of said pocket being disposed to trail themouth as the shell rotates so that a substantial part of material pickedup and carried upwardly by said pocket during rotation of said shell isgradually dropped after the pocket is carried by shell rotation beyondthe uppermost point in rotary movement of said shell.

12. In apparatus for drying various aggregates used in the pavingindustry and the like, a rotatable tubular shell through which the hotdrying gases pass in drying the particulate aggregate material, saidshell being mounted for rotation about its longitudinal axis and havingan inlet for aggregate material at one end and an outlet at the otherend with the rotation axis of said shell inclined downwardly from saidinlet toward said outlet, means for rotating said shell in apredetermined direction, a plurality of material lifting means carriedby and peripherally spaced around the wall of said shell to pick upmaterial from the bottom of said shell as said shell rotates and carrythe material upwardly for release in a free falling curtain extendingtransversely of the shell, each of said lifting means including a wallmember extending inwardly of the wall of said shell and disposed tocarry material upwardly and gradually drop such material to the point atwhich the wall member reaches approximately the uppermost point in therotary movement of said shell and a pocket carried by said shell havinga material retaining portion and a mouth opening into the shellinterior, the material retaining portion of said pocket being disposedto trail the mouth as the shell rotates so that a substantial part ofmaterial picked up and carried upwardly by said pocket during rotationof said shell is gradually dropped after the pocket is carried byrotation of said shell beyond the uppermost point in rotary movement ofsaid shell.

References Cited in the file of this patent UNITED STATES PATENTS1,061,762 Lierfeld May 13, 1913 1,567,335 Scrive Dec. 29, 1925 2,187,601Glaxner Jan. 16, 1940 2,660,408 Laschinger Nov. 24, 1953 FOREIGN PATENTS334,049 Germany Mar. 9, 1921

